ABSTRACT
Poly(ADP-ribose) polymerase-1 (PARP-1) enzyme, as a sensor of DNA damage, could convert nicotinamide adenine dinucleotide (NAD) into long poly(ADP-ribose) chains and regulate many cellular processes, including DNA repair, gene transcription, cell survival and chromatin remodeling. However, excessive activation of PARP-1 depletes its substrate NAD and leads to cell death. Mounting evidences have shown that PARP-1 overactivation plays a pivotal role in the pathogenesis of cardiac hypertrophy and heart failure. In present study, a novel PARP-1 inhibitor AG-690/11026014 (6014) was identified based on virtual screening and validated by bioassay. Our results further showed that 6014 prevented the cardiomyocytes from AngII-induced hypertrophy, accompanying attenuation of the mRNA and protein expressions of atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP), and reduce in the cell surface area. Additionally, 6014 reversed the depletion ofcellular NAD and SIRT6 deacetylase activity induced by AngII in cardiomyocytes. These observations suggest that anti-hypertrophic effect of 6014 might be partially attributed to the rescue of NAD depletion and subsequent restoring of SIRT6 activity by inhibition of PARP-1. Moreover, 6014 attenuated the generation of oxidative stress via suppression of NADPH oxidase 2 and 4, which might probably contribute to the inhibition of PARP-1.
Subject(s)
Cardiomegaly/enzymology , Cardiomegaly/prevention & control , Cardiotonic Agents/therapeutic use , Cytoprotection/drug effects , Enzyme Inhibitors/pharmacology , Myocytes, Cardiac/pathology , Poly(ADP-ribose) Polymerase Inhibitors , Thioglycolates/pharmacology , Xanthines/pharmacology , Angiotensin II , Animals , Cardiotonic Agents/pharmacology , Drug Evaluation, Preclinical , Enzyme Activation/drug effects , Enzyme Inhibitors/analysis , Enzyme Inhibitors/chemistry , Humans , Inhibitory Concentration 50 , Membrane Glycoproteins/metabolism , Molecular Docking Simulation , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/enzymology , NAD/metabolism , NADPH Oxidase 2 , NADPH Oxidase 4 , NADPH Oxidases/metabolism , Poly(ADP-ribose) Polymerases/metabolism , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Recombinant Proteins/metabolism , Sirtuins/metabolism , Thioglycolates/analysis , Thioglycolates/chemistry , Up-Regulation/drug effects , Xanthines/analysis , Xanthines/chemistryABSTRACT
A new strain of Alcaligenes xylosoxydans able to aerobically cometabolize thiodiglycol, the primary hydrolysis product of sulfur mustard, was isolated and tested in a laboratory scale stirred tank reactor. The strain, named PGH10, cannot use TDG as sole carbon and energy source for growth, but resting cells previously grown on either rich broth or defined mineral media efficiently metabolize this compound through [(2-hydroxyethyl)thio]acetic acid and thiodiacetic acid as intermediates. Degradation of TDG by PGH10 is shown to take place at late exponential and stationary phase but is not triggered by carbon exhaustion. Cultures pregrown to saturation for 48 h in the absence of TDG can be stored and used for degradation of TDG, reducing significantly the time required to achieve the reduction of the compound concentration to undetectable levels. Degradation can take place in buffered media with no carbon source added, although best results were obtained in mineral media supplemented with citrate or fructose. Oxidation to [(2-hydroxyethyl)thio]acetic acid and thiodiacetic acid was proposed to be catalyzed by a butanol-dehydrogenase activity. Inhibition of TDG transformation in the presence of several alcohols is also shown.